The Collaborative International Dictionary of English v.0.48:

Corrupt \Cor*rupt"\ (k?r-r?pt"), v. i.
   1. To become putrid or tainted; to putrefy; to rot. --Bacon.
      [1913 Webster]

   2. To become vitiated; to lose purity or goodness.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Corrupt \Cor*rupt"\, v. t. [imp. & p. p. Corrupted; p. pr. &
   vb. n. Corrupting.]
   1. To change from a sound to a putrid or putrescent state; to
      make putrid; to putrefy.
      [1913 Webster]

   2. To change from good to bad; to vitiate; to deprave; to
      pervert; to debase; to defile.
      [1913 Webster]

            Evil communications corrupt good manners. --1. Cor.
                                                  xv. 33.
      [1913 Webster]

   3. To draw aside from the path of rectitude and duty; as, to
      corrupt a judge by a bribe.
      [1913 Webster]

            Heaven is above all yet; there sits a Judge
            That no king can corrupt.             --Shak.
      [1913 Webster]

   4. To debase or render impure by alterations or innovations;
      to falsify; as, to corrupt language; to corrupt the sacred
      text.
      [1913 Webster]

            He that makes an ill use of it [language], though he
            does not corrupt the fountains of knowledge, . . .
            yet he stops the pines.               --Locke.
      [1913 Webster]

   5. To waste, spoil, or consume; to make worthless.
      [1913 Webster]

            Lay not up for yourselves treasures upon earth,
            where moth and rust doth corrupt.     --Matt. vi.
                                                  19.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Corrupt \Cor*rupt`\ (k?r-r?pt"), a. [L. corruptus, p. p. of
   corrumpere to corrupt; cor- + rumpere to break. See
   Rupture.]
   1. Changed from a sound to a putrid state; spoiled; tainted;
      vitiated; unsound.
      [1913 Webster]

            Who with such corrupt and pestilent bread would feed
            them.                                 --Knolles.
      [1913 Webster]

   2. Changed from a state of uprightness, correctness, truth,
      etc., to a worse state; vitiated; depraved; debased;
      perverted; as, corrupt language; corrupt judges.
      [1913 Webster]

            At what ease
            Might corrupt minds procure knaves as corrupt
            To swear against you.                 --Shak.
      [1913 Webster]

   3. Abounding in errors; not genuine or correct; as, the text
      of the manuscript is corrupt.
      [1913 Webster]

WordNet (r) 3.0 (2006):

corrupt
    adj 1: lacking in integrity; "humanity they knew to be
           corrupt...from the day of Adam's creation"; "a corrupt
           and incompetent city government" [ant: incorrupt]
    2: not straight; dishonest or immoral or evasive [syn:
       crooked, corrupt] [ant: square, straight]
    3: containing errors or alterations; "a corrupt text"; "spoke a
       corrupted version of the language" [syn: corrupt,
       corrupted]
    4: touched by rot or decay; "tainted bacon"; "`corrupt' is
       archaic" [syn: corrupt, tainted]
    v 1: corrupt morally or by intemperance or sensuality; "debauch
         the young people with wine and women"; "Socrates was
         accused of corrupting young men"; "Do school counselors
         subvert young children?"; "corrupt the morals" [syn:
         corrupt, pervert, subvert, demoralize,
         demoralise, debauch, debase, profane, vitiate,
         deprave, misdirect]
    2: make illegal payments to in exchange for favors or influence;
       "This judge can be bought" [syn: bribe, corrupt, buy,
       grease one's palms]
    3: place under suspicion or cast doubt upon; "sully someone's
       reputation" [syn: defile, sully, corrupt, taint,
       cloud]
    4: alter from the original [syn: corrupt, spoil]

Moby Thesaurus II by Grady Ward, 1.0:

327 Moby Thesaurus words for "corrupt":
   abandoned, abase, aberrant, abroad, abuse, adrift, adulterate,
   afflict, aggrieve, alienate, all abroad, all off, all wrong, alloy,
   amiss, amoral, approach, approachable, askew, astray, at fault,
   awry, bad, baneful, bastardize, befoul, benasty, beside the mark,
   bewitch, blight, brainwash, break down, break up, bribable, bribe,
   buy, buy off, buyable, canker, cankered, carious, cheapen, coarsen,
   condemn, confound, conscienceless, contaminate, contaminated,
   corrupted, corruptible, counterindoctrinate, criminal, crooked,
   crucify, crumble, crumble into dust, curse, cut, damage, dark,
   debase, debased, debauch, debauched, decadent, decay, decayed,
   deceptive, decompose, decomposed, defective, defile, deflower,
   degenerate, degrade, degraded, deleterious, delusive, demoralize,
   denaturalize, denature, deprave, depraved, desecrate, despoil,
   destroy, detrimental, devalue, deviant, deviational, deviative,
   devious, dial, dilute, disadvantage, dishonest, dishonorable,
   disintegrate, disserve, dissolute, distort, distorted, distress,
   do a mischief, do evil, do ill, do wrong, do wrong by, doctor,
   doctor up, doom, doubtful, dubious, envenom, errant, erring,
   erroneous, evasive, evil, face, fall into decay, fall to pieces,
   fallacious, false, faultful, faulty, features, felonious, fester,
   festering, fishy, fix, fixable, flagitious, flawed, fortify, foul,
   fraudulent, gangrene, gangrened, gangrenous, get at,
   get into trouble, get to, go bad, go to pieces, gone bad, grease,
   grease the palm, harass, harm, heretical, heterodox, hex, hurt,
   ill-got, ill-gotten, illogical, illusory, immoral, impair,
   indirect, indoctrinate, infamous, infect, injure, insidious, jinx,
   kisser, lace, low, maltreat, map, menace, mess, mess up, mildew,
   misadvise, miscreant, misdirect, miseducate, misguide, misinform,
   misinstruct, mislead, misteach, mistreat, misuse, mold, molder,
   molest, morally polluted, mortified, mortify, mug, mystify, nasty,
   necrose, necrosed, necrotic, nefarious, not kosher, not right,
   not true, noxious, obfuscate, oblique, obscure, off, off the track,
   on the pad, on the take, out, outrage, pan, pay off, peccant,
   pernicious, persecute, perverse, pervert, perverted, phiz,
   play havoc with, play hob with, poison, pollute, polluted,
   prejudice, profligate, prostitute, purchasable, purchase, puss,
   putrefied, putrefy, putresce, putrescent, putrid, questionable,
   rankle, ravage, ravish, reach, reindoctrinate, reprobate, rot,
   rotten, rotting, ruin, savage, scathe, self-contradictory, shady,
   shameless, shifty, sinister, slippery, smirch, soil, sphacelate,
   sphacelated, spike, spoil, spoiled, stain, steeped in iniquity,
   straying, suborn, subvert, subverted, sully, suppurate,
   suppurating, suppurative, suspicious, taint, tainted, take care of,
   tamper with, tarnish, threaten, tickle the palm, torment, torture,
   tricky, turn, twist, ulcerate, ulcerated, unconscienced,
   unconscientious, unconscionable, underhand, underhanded, unethical,
   unfactual, unorthodox, unprincipled, unproved, unsavory,
   unscrupulous, unstraightforward, untrue, untrustworthy, venal,
   vice-corrupted, vicious, villainous, violate, visage, vitiate,
   vitiated, vulgarize, warp, warped, water, water down, wicked, wide,
   win away, without remorse, without shame, wound, wreak havoc on,
   wreck, wrong